[Primary diffuse meningeal melanomatosis. Case report].

Melanoma malignum constitutes only 0.1% of central nervous system neoplasms. It can occur either as a solid tumour or as a diffuse meningeal melanomatosis. A case of the latter form of central nervous system melanoma is presented in a 44-year-old man, suffering from headaches, cerebrospinal fluid protein elevation, optic disc oedema, hydrocephalus, seizures, cranial nerves and multilevel spinal root damage. Above mentioned neurological manifestations gradually increased within 18 months after onset of first symptoms of the disease (headache). The clinical course in our patient suggested diffuse leptomeningeal involvement. Despite the use of detailed diagnostic procedures, the correct diagnosis of primary diffuse meningeal melanomatosis was established at postmortem examination. We present our case because of the casuistic rarity of primary diffuse meningeal melanomatosis coexisting with obstructive hydrocephalus resulting from, among other things, extensive neoplastic infiltration of the vertebral channel, especially the cauda equina.